TM 1-1520-240-10
4-4-2
capacity of 800 to 820 gallons of usable fuel and empty
weight of approximately 607 pounds (fig. 4-4-1). ERFS
II tanks are designed to be loaded and unloaded by four
persons (with restraint system in place) in no more than
10 minutes and require no tools. The tanks should not be
unloaded with any quantity of remaining fuel. When the
tanks are installed there is an aisle up the right side of the
aircraft which is approximately 25 inches wide. The
plumbing module consists of an aluminum access cover
secured to an energy-absorbing aluminum tube or col-
umn. The in-tank plumbing components are attached to
a column in the center of the tank permitting easy remov-
al and maintenance on components. A 75 psi fuel cap,
dual transfer pumps, fuel quantity probe, fuel sampling
tube, and a fuel pressure switch are the internal parts of
each of the tanks. Refueling the ERFS II tanks is per-
formed by either the helicopter Single Point Refueling
System or gravity.
a.
Fuel Hoses. An interconnecting fuel hose man-
ifold connects the ERFS II tanks together. A two inch
hose connected at the forward end of the ERFS II fuel
manifold is connected to the helicopter Single POINT
Refueling System in the vicinity of STA 225 on the left
side of the cargo compartment. Fuel transfer hoses con-
nected at the aft end of the manifold carry fuel to the
aircraft fuel system quick disconnects at STA 380 on both
left and right sides of the cargo compartment.
CAUTION
Up to 4 OZ. of fuel can be trapped between
the closed “Dry Break” valves in the Uni-
sex couplings. Care should be taken to
minimize spillage of this trapped fuel
when separating the couplings.
b.
Vent Hose Assembly. Aircraft overboard vents
and connections are installed on the left side of the cabin
area through the fuselage at STA 254.0, 330.0, and
410.0. Overboard fuel vent caps must be removed any-
time internal fuel tanks are installed. Vent hoses are con-
nected to the tank vent line at the self-sealing breakaway
valve on the top of the tank assembly and one of the three
aircraft overboard vent connections.
CAUTION
Trying to pressure refuel the tanks without
connecting the vent line could overpres-
surize the tanks.
The vent hose assembly allows the venting to atmo-
sphere of fuel vapor, thus providing vent air to relieve
internal tank pressures. Fuel hoses and manifold are
self-sealing incorporating Unisex couplings. Each Uni-
sex coupling, ballcock valve, permits hose removal with-
out fuel spillage. The manifold also provides connection
to the FARE pump module. The fuel/defuel valve is a
manually operated vented valve that simultaneously
opens a high flow rate fuel path in the fuel/defuel line, and
a high flow rate vent path out of the tank. The valve must
be open for pressure refueling of the tanks, FARE opera-
tions, or suction defueling. An automatic fuel shutoff
valve, with dual high level shutoff controls is located in-
side the tank. Inside each of the tanks is an open vent
valve to allow fuel to vent overboard in the event of high
level shutoff valve failure.
